JP2003504631A - Sensor device for detecting wetness of glass - Google Patents

Abstract

(57) Abstract: A sensor device has been proposed for detecting wetness on glass (13), especially due to rainfall and / or dirt, the sensor device comprising at least one transmitter (14). , At least one receiver (15) for transmitter light (17) emitted from the transmitter, wherein the transmitter (14) and the receiver (15) are located at the corners of a virtual trapezoid. Are located. This reduces the outer dimensions of the sensor, improves the ratio of the light receiving surface (19) to the reference surface (18) of the sensor, and provides a continuous light receiving surface, in which case the automatic light control device has a receiving element for the receiving element. Space is also provided.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION The invention starts from a sensor device for detecting the wetness of glass according to the preamble of claim 1.

From the German patent application DE 197 01 258 A1 a sensor device is known for controlling a wiper device for a vehicle glass which operates in an optoelectronic manner. The sensor device comprises a plurality of transmitters and at least one receiver, which couple a given beam into and out of the glass via coupling means, so that due to moisture or dirt. The wetness of the glass is measured. The transmitter is arranged concentrically or partially concentrically around the receiver in the coupling means, the coupling means being formed in a circular or ring shape. A circular reference plane is formed by the transmitter, the receiver and the coupling means. The sensor or sensor casing is formed in a cylindrical shape based on the reference plane.

Advantages of the invention Advantageously, with the sensor device according to the invention having the features of claim 1, a significant improvement in the reaction state of the sensor device is obtained, the improvement being the ratio of the photosensitive surface to the mounting surface. Caused by increasing. This is achieved by the trapezoidal arrangement of transmitter and receiver. This is because a vertically long continuous light receiving surface is generated, which increases the probability that raindrops located on the glass will flow to the photosensitive surface by the traveling wind. The result is a marked improvement in the reaction conditions.

[0004]   Further advantages of the invention are apparent from the features of the dependent claims.

The use of multiple receivers per transmitter increases the number of measurement lines and thus the number of photoconductor surfaces, which has a cost advantage. A similar effect occurs when multiple transmitters and a single receiver are used. If two transmitters and two receivers are used, four measuring line segments are obtained, and thus four photosensitive surfaces. If the distance between the two transmitters and the distance between the two receivers are of the order of 2: 1, a particularly even arrangement of the photosensitive surface is obtained.

Furthermore, it is advantageous to mount the sensor device on the glass such that the transmitter is arranged in the assembled lower parallel lines of the trapezoid and the receiver is arranged in the upper parallel lines. In that way, solar radiation, which is advantageously obtained from above and which constitutes undesired external light, can be minimized at the receiver.

By improving the properties, in particular the ratio between the light-receiving surface and the mounting surface, the mounting surface of the sensor can be reduced, which reduces the outer dimensions of the sensor with respect to the glass. It Particularly advantageously, despite the trapezoidal arrangement of transmitter and receiver, the outer dimensions of the sensor casing can be chosen to be rectangular, so that the mounting surface of the optical waveguide is used in an optimal manner. At the same time, the reference surface can be arranged on the mounting surface. In addition, the rectangular mounting surface or casing reduces the manufacturing cost. Moreover, the small mounting surface of the optical waveguide provides significant mounting advantages.
This is because the pressing force is increased when the pressing force is constant, which makes it possible to avoid inconvenient bubble formation between the binding medium and the glass.

It is further advantageous if the two transmitters or receivers are located parallel to each other on opposite sides. Significant cost advantages are obtained if the four measuring lines of the sensor, ie the four light-receiving surfaces, are realized solely by two transmitters and two receivers, respectively.

[0009] According to an advantageous embodiment of the sensor device, for example, German Patent No. 19
An automatic light controller (ALS) as described in 630216 is integrated in the raindrop sensor module. The receiving optical system of the automatic light control device (ALS) can detect a wide area around the vehicle by the direction sensor technology and the global sensor technology. For example, a tunnel entry can be timely recognized before entry by the directionally directed detection cone (Erfassungskegel) of the direction sensor technology. Due to the trapezoidal arrangement of transmitter and receiver, sufficient space for the receiving optics is maintained in the center of the sensor in spite of its compact construction. In this case, the trapezoid preferably has long and short parallel lines. This is because the receiving optics can additionally extend towards the larger parallel lines without increasing the overall dimensions of the sensor.

[0010]     Example description   Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a sectional view of an optical waveguide 10 of a sensor device having a sensor casing 11. The mounting surface of the optical waveguide 10 is provided by the contact between the optical waveguide 10 and the glass 13 via the coupling medium 12 (for example, a silicone cushion), for example. In general, the outer dimensions of the optical waveguide 10 correspond approximately to the length and width dimensions of the sensor device, in which case the sensor casing 11 is swollen and the contact mounting of the optical waveguide 10 above the glass 13 is carried out. It may project beyond the mounting surface and accommodates different elements of the sensor device (in particular transmitter 14, receiver 15 and switch board 24) inside the casing.

For example, the sensor device is mounted inside the glass 13 (for example, the windshield of the vehicle). The mounting of the glass 13 and the sensor casing 11 is not shown. Advantageously, the optical waveguide 10 or the sensor casing 11 is attached to the glass 13 by a press fit. The optical waveguide 10 couples the transmitter light 17 emitted from the transmitter 14 into the glass 13, and receives the transmitter light 20 deflected by total reflection or reflection in the glass 13 at another set position. It has a function of output coupling to the device 15. This function is provided by an optical element 16 which is attached (preferably integrally molded) to the optical waveguide as a lens and which focuses, deflects or redirects the beam of transmitter light 17, 20 in the desired direction. can get.

In the cross section shown, inside the sensor casing 11 and above the optical waveguide 10, at least one light-emitting transmitter 14 and a light-detecting receiver 15 are mounted. Light-emitting diodes (LEDs) are preferably used as transmitters and photo-detecting diodes (LRDs) are preferably used as receivers, where the transmitter beam of light is in the infrared (IR) or visible range. (VIS) exists, and another arbitrary frequency region can be realized. As a receiver, it is also possible to use a receiving element structurally corresponding to a light emitting diode, whereby the transmitter 14
Optimal frequency matching between the receiver and the receiver 15 is achieved. As a material for the light guide 10, a plastic material is selected which is transparent to the transmission frequency of the light emitting diode (LED) but impermeable to the harmful external light.

FIG. 2 shows a possible arrangement of the transmitter 14 and the receiver 15.
The transmitter 14 and the receiver 15 of the sensor device are arranged near the optical element 16 shown in FIG. Transmitter 14, receiver 15 and optical element 1 to which they belong
6 forms a reference plane 18 indicated by a chain line, and according to the invention this reference plane 1
8 is a trapezoid.

On the first parallel line of the trapezoid, two optical elements 16 are arranged near the transmitter 14, respectively. Due to the fact that the optical element 16 is formed as two lenses which are adjacent to each other, two measuring lines in two directions are produced for each transmitter 14. Similarly to this, the receiver 15 is arranged. The optical element 16 is formed, for example, of a lens or a mirror, which may be displaced from each other. It is also possible to implement components that only have one lens each. This is because the loss angle that occurs can be maintained slightly by properly selecting the spacing 18a and the spacing b of the trapezoidal reference surface 18.

The distance “a” or the distance “b” between the transmitter 14 and the receiver 15 depends on the wavelength of the irradiation beam of the transmitter 14, the thickness of the glass 13, and the thickness of the optical waveguide 10. Rate, the angle of entry of the transmitter light 17 into the glass 13 and the location of entry. That is, said spacing is such that the beam of transmitter light 17 that is coupled into the glass 13 is totally reflected once on each measuring line segment on the surface located outside the glass 13, and then is coupled out of the glass 13 to the receiver 15. Selected to be guided.

The light-sensitive surface 19 shown schematically corresponds to the region of the wettable surface of the glass 13, on which the light of the transmitter light 17 is emitted while the glass 13 is dry. Total reflection of the beam is performed. Depending on the arrangement of the transmitter 14 and the receiver 15 with respect to the glass 13, the thickness of the glass 13, and the shape of the optical element 16, the transmitter light 17
Has a predetermined diameter. According to the invention, these described parameters are
It is desirable that the size be such that a substantially continuous photosensitive surface 19 is formed from each reflecting surface. This means that, according to the invention, the intersections of the central axis of the cone beam 20 of the transmitter 14 and the wettable surface of the glass 13 are located linearly and are substantially equidistant. To be achieved.

If more than one total internal reflection of the wettable outer surface of the glass 13 is desired, the spacing between the transmitter 14 and the receiver 15 or the desired optical element 16 respectively. The distance a or the distance b should be selected to be appropriately large, and the coupling medium 12 should be attached to the glass 13 only in the ingress coupling region and the egress coupling region of light.

FIG. 3 shows an optical waveguide 10 of the sensor device according to the invention shown in FIG. Since the trapezoid formed by the transmitter 14 and the receiver 15 has large and small parallel lines, the receiving optical system 21 for automatic light control of the vehicle is slightly shifted from the center toward the larger parallel line. Are arranged. The receiving optical system 21 is made of a light transmissive material, and its transmissive region exists in the visible region.

The optical waveguide 10 and the receiving optical system 21 are integral with each other, and are manufactured by, for example, a multi-component injection molding method, and it is possible to realize a configuration including a plurality of independent parts. The system 21 is injection molded into suitable notches in the optical waveguide 10.

Here, the receiving optical system 21 itself includes four elements 22 formed in a substantially lens shape,
Equipped with 23. In the sensor casing, near the lens-shaped elements 22 and 23,
One or more daylight sensors, not shown here, are attached,
With these sensors, the brightness state of the surrounding environment of the vehicle can be detected with directivity. The first element 23 of the lenticular elements 22 and 23 is formed so as to detect the overall brightness of the vehicle surrounding environment regardless of the direction. The remaining three lens-shaped second elements 22 are narrow detection light cones (Lichterfassungskegel), which have three different directions in front of the vehicle, which allow early recognition of tunnel entry, for example. In particular, it can be recognized at a time when these lenticular elements are not yet clearly positioned in the direction of travel.

Plexiglas (PMMA) is often used as the material of the optical waveguide 10. This is because plexiglass is inexpensive and can be processed well. However, other plastics are also conceivable, since transparency is only required in the region of the transmitter light. Also particularly suitable are optical waveguide materials which have a softer and more elastic property on the side facing the glass 13, for example by chemical or physical methods, than on the side opposite the glass 13. This is because the coupling medium 12 can be omitted.

In order to obtain the filtering properties of the optical waveguide 10, certain materials (especially carbon black powder) can be spatially selected and added to the optical waveguide material during the fabrication process of the optical waveguide 10. . In that way, for example, only the areas functionally required for the transmitter light 17 may be transparent. A similar operation type can be realized for the coupling medium 12.

In another embodiment, transmitter 14 and receiver 15 are placed at each corner of the trapezoid, or
Alternatively, only one transmitter 14 for the entire trapezoid can be used. In this case, the optical element 16 has a reflective property, which allows the glass 13 to be coupled in at a plurality of corner points of the trapezoid.

The receiving optical system 21 may include a large number of elements 22 and 23, in particular facets.
A configuration is feasible, and such a configuration can consider the spatial configuration and accurately evaluate the brightness distribution. Thereby, for example, an oncoming vehicle can be recognized. Of course, the optical frequencies can also be filtered. Based on satisfying such information, for example, the high beam and the low beam can be switched automatically or semi-automatically.

[Brief description of drawings]

[Figure 1]   It is sectional drawing which shows schematically the Example of the optical system part of the sensor apparatus of this invention.

[Fig. 2]   It is the schematic which shows the outline of the Example of the sensor apparatus of this invention.

FIG. 3 is a perspective view showing an optical waveguide of the sensor device according to the invention according to FIG. 1 with receiving optics for an automatic light control device.

[Explanation of symbols]

10 optical waveguide, 11 sensor casing, 12 coupling medium, 13 glass, 14 transmitter, 15 receiver, 16 optical element, 17 transmitter light, 18 reference surface, 19 photosensitive surface, 20 transmitter light, 21 receiving optical system ,
22, 23 lens-like elements, 24 switch substrate

─────────────────────────────────────────────────── ─── Continued front page    (72) Andreas Gilet, the inventor             Germany Bühl Beethove             Enstraße 11 (72) Inventor Bruno Hodup             Federal Republic of Germany Ahern-Ensba             Bach Katzenfeld 7 (72) Inventor Gephard Michenfelder             Federal Republic of Germany Richtenau             Art hark 21 (72) Inventor Liner Pientka             Federal Republic of Germany Renchen Cloak             Sveke 12 (72) Inventor Hans Meier             Federal Republic of Germany Ottersweier               Mosslandstrasse 49 (72) Inventor Henry Blitzke             Federal Republic of Germany Buhl Forren             Strasse 3 (72) Inventor Manfred Bullcult             Ifetsheim Bena, Germany             Zett Strasse 6 F term (reference) 2G059 AA05 BB02 CC11 EE02 GG02                       GG03 HH01 HH02 JJ11 KK01                       KK03                 3D025 AG39 AG42

Claims (14)

[Claims] 1. A sensor device for detecting the wetness of a glass (13) which is in particular a windshield of a vehicle, in particular due to rain and / or dirt, which sensor device comprises at least one transmitter ( 14) and at least one receiver (15) between the glass (13) and the transmitter (14) or the glass (13).
And a receiver (15) for the beam emitted from at least one transmitter (14)
) And an optical waveguide (10) provided between the transmitter (14) and the receiver (15) projected onto the glass (13) are trapezoidal. A sensor device for detecting wetness of glass, which is characterized by forming corner points. 2. The beam between the transmitter (14) and the receiver (15) is glass (
At least once on the surface of 13) such that at least one of the transmitters (14) emits the beam in different directions so that the resulting reflective surface forms at least a substantially continuous photosensitive surface (19). The sensor device according to claim 1, wherein 3. At least one transmitter (14) directs a beam in two directions.
2. The sensor device according to claim 1, which is adapted to emit to one receiver (15). 4. Sensor device according to claim 1 or 3, wherein at least one receiver (15) is adapted to receive beams in two directions from two transmitters (14). 5. The sensor device according to claim 1, wherein two transmitters (14) and two receivers (15) are provided. 6. The trapezoid is a symmetrical trapezoid, the spacing between two transmitters (14) being different from the spacing between two receivers (15), one spacing being the other spacing. 6. The sensor device according to claim 5, wherein the sensor device is doubled. 7. A sensor device having four measuring line segments.
The sensor device according to any one of items 1 to 7. 8. The transmitter (14) is arranged on the lower first parallel line in the assembled state, and the receiver (15) is arranged on the upper second parallel line in the assembled state. The sensor device according to claim 5. 9. At least one transmitter (14) in the glass (13)
2. The centers of the plurality of reflecting surfaces of the cone beam (20) of said at least approximately equidistant from one another, preferably on a straight line lying between both parallel lines of the trapezoid. 9. The sensor device according to any one of 1 to 8. 10. An optical waveguide (10), a transmitter (14) and a receiver (15).
However, the total reflection of the transmitter light (17) is performed only once on the glass (13),
The sensor device according to any one of claims 1 to 9, which is formed. 11. A transmitter (14) in each of the optical waveguides (10).
Alternatively, an optical element (16) is associated with the receiver (15), which optical element (16) in particular comprises two separate lenses. The described sensor device. 12. The sensor device according to claim 11, wherein the lenses are moved to each other. 13. A receiver (14) in each of the optical waveguides (10).
Alternatively, the sensor device according to any one of claims 1 to 10, wherein an optical element (16) is associated with the transmitter (15) and the optical element (16) comprises only one lens. 14. A receiving optical system (21) for an automatic light control device is arranged in an optical waveguide (10), which is arranged in the center or offset towards a larger parallel line, for receiving. 13. The sensor device according to any one of 13 to 13.